Definition

Noun: 1. A taxonomic subclass: In certain biological classification systems, 'subclass Infusoria' is a taxonomic rank that is coextensive with (i.e., contains the same organisms as) the class Ciliata. It consists of minute, single-celled organisms (ciliates) commonly found in decomposing infusions of organic matter, such as hay or plant material in water.

Usage Notes

• This term is primarily used in the context of historical or specialized biological taxonomy. In modern classifications, the term 'Ciliophora' (phylum) or 'Ciliata' (class) is more commonly used.
• The name 'Infusoria' originates from the organisms' traditional discovery method: they appear in 'infusions' of organic material left in water.

Examples

• Scientific Context:
  • The researcher studied various microorganisms, including those belonging to the subclass Infusoria, under the microscope.
  • In older textbooks, you might find Paramecium classified under subclass Infusoria.

Advanced Usage

• Historical Classification: The term can be used to discuss the evolution of biological taxonomy.
  • The concept of subclass Infusoria illustrates how microbial classification has changed with improved microscopic techniques.

Variants and Related Words

• Infusoria (noun, plural): Often used as a common name for the group of organisms themselves, not just the taxonomic rank.
  • The pond water teemed with infusoria.
• Ciliate (noun): A member of this group of organisms, characterized by hair-like structures called cilia.
  • The ciliate used its cilia for movement and feeding.
• Ciliophora (noun): The modern phylum name encompassing these organisms.

Synonyms

• Ciliata (in taxonomic contexts where the terms are considered coextensive).

Noun

1. in some recent classifications, coextensive with the Ciliata: minute organisms found in decomposing infusions of organic matter